Power amplifiers are utilized in communications systems to produce sufficient transmitter power to maintain adequate signal to noise ratio. Solid state power amplifiers are particularly desirable because they are efficient and of compact size requiring low voltage power supplies.
The present invention addresses the problem of devising efficient power combining networks, power combining branching systems, or power combining trees for microwave frequencies. Individual solid state amplifiers, monolithic microwave integrated circuits (MMICs), are capable of producing at their output ports moderate power levels. At X band, 15 watts appears to be the nominal output power maximum available. Often the system power requirement surpasses this level by an order of magnitude. A 200 watt output would require the combining of many such MMICs and orthodox multi-port power combiners based on microstrip lines are lossy and therefore inefficient. The present invention allows the achievement of a 200 watt power using just sixteen MMICs at 15 watts each. The equivalent loss would be 40 watts in a potential 240 watts or less than 1.0 dB loss in the combiner.